Muscle inhibition can occur anywhere. In this case it is apparent during a lunge. One leg is able while the other has ranges that struggle. There are 13 divisions of the quadriceps muscle. This change was a result of treating 2 of those muscles.
Simple concept, if a muscle won’t accept load as it should the force must be transferred and absorbed by a neighboring muscle, which alters the direction and management of forces. This can result in pain, dysfunction, decreased performance, and even inability to perform daily tasks. Once the muscle can be loaded, those shifts no longer occur and the muscles can be strengthened and used the way they should, pain changes or leaves, and functions return just that fast.